oj.uz

Submission #372829

# Submission time Handle Problem Language Result Execution time Memory
372829 2021-03-01T21:31:56 Z luciocf Circle selection (APIO18_circle_selection) C++14
23 / 100
 742 ms 35376 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int maxn = 3e5+10;
const int add = 1e9;

ll R;

struct Circle
{
	ll x, y, r;
	int ind;

	bool operator<(const ll &o) const
	{
		return y/R < o;
	}
} circle[maxn];

vector<vector<Circle>> V;

int ans[maxn];

bool comp1(Circle a, Circle b)
{
	if (a.x/R == b.x/R) return a.y < b.y;
	return a.x < b.x;
}

bool comp2(Circle a, Circle b)
{
	if (a.r == b.r) return a.ind < b.ind;
	return a.r > b.r;
}

bool intersect(Circle a, Circle b)
{
	ll dx = a.x-b.x, dy = a.y-b.y, dr = a.r+b.r;

	return dx*dx + dy*dy <= dr*dr;
}

void doit(int pos, int c)
{
	ll y = circle[c].y;

	ll l_y = y/R - 2, r_y = y/R + 3;

	auto it = lower_bound(V[pos].begin(), V[pos].end(), l_y);
	for (; it != V[pos].end() && it->y/R <= r_y; it++)
		if (intersect(circle[c], *it) && !ans[it->ind])
			ans[it->ind] = circle[c].ind;
}

int main(void)
{
	int n;
	scanf("%d", &n);

	for (int i = 1; i <= n; i++)
	{
		scanf("%lld %lld %lld", &circle[i].x, &circle[i].y, &circle[i].r);
		circle[i].x += add, circle[i].y += add;
		circle[i].ind = i;
	}

	R = circle[1].r;

	sort(circle+1, circle+n+1, comp1);

	for (int i = 1; i <= n; i++)
	{
		if (i == 1 || circle[i].x/R > circle[i-1].x/R)
			V.push_back(vector<Circle>());

		V.back().push_back(circle[i]);
	}

	sort(circle+1, circle+n+1, comp2);

	for (int i = 1; i <= n; i++)
	{
		if (ans[circle[i].ind]) continue;

		ll x = circle[i].x;

		ll l_x = x/R - 2, r_x = x/R + 3;

		int p_l, p_r;

		int ini = 0, fim = (int)V.size()-1;

		while (ini <= fim)
		{
			int mid = (ini+fim)>>1;

			if (V[mid][0].x/R >= l_x) p_l = mid, fim = mid-1;
			else ini = mid+1;
		}

		ini = 0, fim = (int)V.size()-1;

		while (ini <= fim)
		{
			int mid = (ini+fim)>>1;

			if (V[mid][0].x/R <= r_x) p_r = mid, ini = mid+1;
			else fim = mid-1;
		}

		for (int j = p_l; j <= p_r; j++)
			doit(j, i);
	}

	for (int i = 1; i <= n; i++)
		printf("%d ", ans[i]);
	printf("\n");
}

Compilation message

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:61:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   61 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
circle_selection.cpp:65:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   65 |   scanf("%lld %lld %lld", &circle[i].x, &circle[i].y, &circle[i].r);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
circle_selection.cpp:92:12: warning: 'p_r' may be used uninitialized in this function [-Wmaybe-uninitialized]
   92 |   int p_l, p_r;
      |            ^~~
circle_selection.cpp:114:3: warning: 'p_l' may be used uninitialized in this function [-Wmaybe-uninitialized]
  114 |   for (int j = p_l; j <= p_r; j++)
      |   ^~~

Subtask #1
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Incorrect 0 ms 364 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 288 ms 22640 KB Output is correct
2 Correct 295 ms 24528 KB Output is correct
3 Incorrect 286 ms 23396 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 364 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 742 ms 27932 KB Output is correct
2 Correct 742 ms 34712 KB Output is correct
3 Correct 386 ms 23788 KB Output is correct
4 Correct 727 ms 35376 KB Output is correct
5 Correct 725 ms 34712 KB Output is correct
6 Correct 366 ms 21996 KB Output is correct

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Incorrect 0 ms 364 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Incorrect 0 ms 364 KB Output isn't correct
5 Halted 0 ms 0 KB -